Touring Greece, playing instrument (6,7)
I believe the answer is:
geiger counter
'instrument' is the definition.
(I know that Geiger counter is a type of instrument)
'touring greece playing' is the wordplay.
'playing' indicates anagramming the letters.
'touring'+'greece'='touringgreece'
'touringgreece' is an anagram of 'GEIGER COUNTER'.
(Other definitions for geiger counter that I've seen before include "Radiation measurer" , "Particle detector" , "Device for measuring radiation" , "Instrument for measuring radioactivity" .)